U.S. patent number 6,936,265 [Application Number 09/963,161] was granted by the patent office on 2005-08-30 for preparations of the w/o emulsion type with an increased water content based on low-viscosity, readily spreadable lipid components, additionally comprising one or more alkylmethicone copolyols and/or alkyldimethicone copolyols.
This patent grant is currently assigned to Beiersdorf Aktiengesellschaft. Invention is credited to Andreas Bleckmann, Rainer Kropke.
United States Patent |
6,936,265 |
Bleckmann , et al. |
August 30, 2005 |
PREPARATIONS OF THE W/O EMULSION TYPE WITH AN INCREASED WATER
CONTENT BASED ON LOW-VISCOSITY, READILY SPREADABLE LIPID
COMPONENTS, ADDITIONALLY COMPRISING ONE OR MORE ALKYLMETHICONE
COPOLYOLS AND/OR ALKYLDIMETHICONE COPOLYOLS
Abstract
Water-in-oil emulsions (a) having a water phase content of at
least 80% by weight, based on the total weight of the emulsions,
(b) in which the lipid phase comprises at least one lipid with a
viscosity of less than 15 mPa.multidot.s (at 25.degree. C.), which
has a spreading value of at least 700 mm.sup.2 /10 minutes (at
25.degree. C.), (c) at least one interface-active substance chosen
from the group of alkylmethicone copolyols and/or alkyldimethicone
copolyols, (d) if desired also comprising one or more cationic,
nonionic and/or anionic polymers, preferably in concentrations of
from 0.01 to 10% by weight, preferably 0.1 to 5% by weight,
particularly preferably 0.25 to 1% by weight.
Inventors: |
Bleckmann; Andreas (Ahrensburg,
DE), Kropke; Rainer (Schenefeld, DE) |
Assignee: |
Beiersdorf Aktiengesellschaft
(Hamburg, DE)
|
Family
ID: |
7658353 |
Appl.
No.: |
09/963,161 |
Filed: |
September 26, 2001 |
Foreign Application Priority Data
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Sep 30, 2000 [DE] |
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100 48 683 |
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Current U.S.
Class: |
424/401;
424/70.1; 516/21 |
Current CPC
Class: |
A61Q
19/00 (20130101); A61Q 19/10 (20130101); A61K
8/585 (20130101); A61K 8/894 (20130101); A61P
17/00 (20180101); A61Q 17/00 (20130101); A61K
8/064 (20130101); A61K 8/06 (20130101) |
Current International
Class: |
A61K
8/58 (20060101); A61K 8/30 (20060101); A61K
007/00 (); A61K 007/06 (); C09K 003/00 () |
Field of
Search: |
;424/401,70.1
;516/21 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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692 10 515 |
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Nov 1996 |
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DE |
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198 26 750 |
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Dec 1999 |
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DE |
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199 33 463 |
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Jan 2000 |
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DE |
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198 44 261 |
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Mar 2000 |
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DE |
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198 52 212 |
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May 2000 |
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DE |
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Other References
Wenninger et al. `International Cosmetic Ingredient dictionary and
Handbook,` 1997, p. 406..
|
Primary Examiner: Wang; Shengjun
Attorney, Agent or Firm: Norris McLaughlin & Marcus
PA
Claims
What is claimed is:
1. A water in oil emulsion comprising, (a) a water phase content of
at least 80% by weight based on the total weight of the emulsion,
(b) a lipid phase wherein the lipid phase comprises at least one
lipid selected from the group consisting of isoeicosane, octyl
cocoate, neopentyl glycol diheptanoate, propylene glycol
dicaprylate/dicaprate, dibutyl adipate, isodecyl neopentanoate,
dicaprylyl carbonate, dioctylcyclohexane, dihexyl carbonate,
dihexyl ether, cycloparaffin, ethoxy diglycol oleate, ethoxy
diglycol, butylene glycol caprylate/caprate, octyl isostearate,
decylcocoate, dimethyl isosorbide, wherein the at least one lipid
comprises at least 50 wt.-% based on the weight of the lipid phase.
(c) at least one interface active substance chosen from the group
of alkylmethicone copolyols and/or alkyldimeticone copolyols, and
(d) optionally, at least one viscosity enhancing polymer selected
from the group consisting of modified celluloses, acrylate
copolymers, acrylatealkylacrylate copolymers, polyethers, vinyl
polymers, polysilicic acids, clay minerals, polycarboxylic acids or
salts thereof, polyamides and polyimines.
2. The emulsion as claimed in claim 1, wherein the interface-active
substance chosen is cetyldimethicone copolyol.
3. The emulsion as claimed in claim 1, wherein the interface-active
substance chosen is laurylmethicone copolyol.
4. The emulsion as claimed in claim 1, wherein the total amount of
alkylmethicone copolyols and/or alkyldimethicone copolyols is
chosen from 0.075 7.5% by weight, based on the total weight of the
preparation.
5. The emulsion of claim 1, wherein the total amount of
alkylmethicone copolyols and/or alkyldimethicone copolyols is from
0.1 5.0% by weight.
6. The emulsion of claim 5, wherein the total amount of
alkylmethicone copolyols and/or alkyldimethicone copolyols is from
1.0 3.0% by weight, based on the total weight of the
preparation.
7. The emulsion of claim 1 wherein the at least one lipid comprises
at least 80% of the weight of the lipid phase.
8. The emulsion of claim 1 wherein the at less one viscosity
enhancing agent is 0.01% to 10% by weight based on the total weight
of preparation.
9. The emulsion of claim 1 wherein the at least one lipid comprises
at least 80% of the weight of the lipid phase.
10. The emulsion of claim 8 wherein the at least one viscosity
enhancing agent is 0.25% to 1% by weight based on the total weight
of the preparation.
Description
This application claims foreign priority of Germany 100 48 683.5,
filed Sep. 30, 2000.
The present invention relates to cosmetic and dermatological
preparations, in particular those of the water-in-oil type, to
processes for their preparation and to their use for cosmetic and
medicinal purposes.
The human skin is man's largest organ and performs a number of
vital functions. Having an average area of about 2 m.sup.2 in
adults, it has a prominent role as a protective and sensory organ.
The purpose of this organ is to transmit and avert mechanical,
thermal, actinic, chemical and biological stimuli. In addition, it
has an important role as a regulatory and target organ in human
metabolism.
The main aim of skin care in the cosmetics sense is to strengthen
or restore the skin's natural function as a barrier against
environmental influences (e.g. dirt, chemicals, microorganisms) and
against the loss of endogenous substances (e.g. water, natural
fats, electrolytes), and also to assist its horny layer in its
natural regeneration ability in cases of existing damage.
If the barrier properties of the skin are impaired, increased
resorption of toxic or allergenic substances or attack by
microorganisms may result, leading to toxic or allergic skin
reactions.
Another aim of skin care is to compensate for the loss by the skin
of sebum and water caused by daily washing. This is particularly
important if the natural regeneration ability is inadequate.
Furthermore, skin care products should protect against
environmental influences, in particular against sun and wind, and
delay skin ageing.
Medicinal topical compositions usually comprise one or more
medicaments in an effective concentration. For the sake of
simplicity, in order to clearly distinguish between cosmetic and
medicinal use and corresponding products, reference is made to the
legal provisions in the Federal Republic of Germany (e.g. Cosmetics
Directive, Foods and Drugs Act).
Emulsions are generally taken to mean heterogeneous systems which
consist of two liquids which are immiscible or miscible with one
another only to a limited extent, which are usually referred to as
phases. In an emulsion, one of the two liquids is dispersed in the
form of very fine droplets in the other liquid.
If the two liquids are water and oil and oil droplets are very
finely dispersed in water, this is an oil-in-water emulsion (O/W
emulsion, e.g. milk). The basic character of an O/W emulsion is
determined by the water. In the case of a water-in-oil emulsion
(W/O emulsion, e.g. butter), the principle is reversed, the basic
character being determined here by the oil.
The person skilled in the art is of course aware of a large number
of ways to formulate stable W/O preparations for cosmetic or
dermatological use, for example in the form of creams and ointments
which can be spread in the range from room temperature to skin
temperature, or as lotions and milks, which are more likely
flowable in this temperature range. However, there are only a few
formulations in the prior art which are of sufficiently
low-viscosity that they would, for example, be sprayable.
In addition, low-viscosity preparations of the prior art frequently
have the disadvantage that they are unstable, and are limited to a
narrow field of application or a limited choice of feed materials.
Low-viscosity products in which, for example, strongly polar
oils--such as the plant oils otherwise frequently used in
commercially available products--are sufficiently stabilized are
therefore currently not on the market.
The term "viscosity" means the property of a liquid to resist the
mutual laminar displacement of two neighboring layers (internal
friction). This so-called dynamic viscosity is nowadays defined
according to .eta.=.tau./D as the ratio of shear stress to the
velocity gradient perpendicular to the direction of flow. For
Newtonian liquids, .eta. is a material constant having the SI unit
Pascal second (Pa.multidot.s) at a given temperature.
The quotient .nu.=.eta./.rho. from the dynamic viscosity .eta. and
the density .rho. of the liquid is referred to as the kinematic
viscosity .nu. and is given in the SI unit m.sup.2 /s.
Fluidity (.phi.) is the inverse of viscosity (.phi.=1/.eta.). In
the case of ointments and the like, the use value is inter alia
codetermined by the so-called tack. The tack of an ointment or
ointment base or the like means its property to draw threads of
varying lengths when a small sample is removed; accordingly, a
distinction is made between short- and long-stretch substances.
Whilst the graphical representation of the flow behavior of
Newtonian liquids at a given temperature produces a straight line,
in the case of so-called non-Newtonian liquids considerable
deviations often arise, depending on the velocity gradient D (shear
rate.gamma.) or the shear stress .tau.. In these cases, the
so-called apparent viscosity can be determined which, although it
does not obey the Newtonian equation, can be used to determine the
true viscosity values by graphical methods.
Falling-body viscometry is suitable only for investigating
Newtonian liquids and gases. It is based on Stokes's law, according
to which, for the falling of a sphere through a liquid which flows
around it, the dynamic viscosity .eta. can be determined from
##EQU1##
where
r=radius of the sphere, v=fall velocity, .rho..sub.K =density of
the sphere, .rho..sub.FI =density of the liquid and g=acceleration
of the fall.
The viscosity values of the preparations and individual substances
listed within the scope of the present disclosure were determined
using a Viscotester VT 02 type viscometer from the company
Haake.
W/O emulsions with a high water content and a low viscosity which
moreover have storage stability, as is required for marketable
products, can only be formulated with difficulty according to the
prior art. Accordingly, the supply of such formulations is
extremely small. Nevertheless, such formulations could offer the
consumer hitherto unknown cosmetic effects.
An object of the present invention was to provide preparations
which have a very low viscosity and do not have the disadvantages
of the prior art.
Another object of the present invention was to provide preparations
which can be laden with a high content of water-soluble and/or
water-miscible substances having cosmetic or dermatological
effectiveness, without impairing the galenical quality or other
properties of the preparations.
Surprisingly, it has been found that water-in-oil emulsions (a)
having a water phase content of at least 80% by weight, based on
the total weight of the emulsions, (b) in which the lipid phase
comprises at least one lipid with a viscosity of less than 15
mPa.multidot.s (at 25.degree. C.), which has a spreading value of
at least 700 mm.sup.2 /10 minutes (at 25.degree. C.), (c) at least
one interface-active substance chosen from the group of
alkylmethicone copolyols and/or alkyldimethicone copolyols, (d) if
desired also comprising one or more cationic, nonionic and/or
anionic polymers, preferably in concentrations of from 0.01 to 10%
by weight, preferably 0.1 to 5% by weight, particularly preferably
0.25 to 1% by weight,
are able to achieve these objects.
According to the invention, the silicone emulsifiers can
advantageously be chosen from the group of interface-active
substances from the group of alkylmethicone copolyols and/or
alkyldimethicone copolyols, in particular from the group of
compounds characterized by the following chemical structure:
##STR1##
in which X and Y, independently of one another, are chosen from the
group H, and of branched and unbranched alkyl groups, acyl groups
and alkoxy groups having 1-24 carbon atoms, p is a number from
0-200, q is a number from 1-40, and r is a number from 1-100.
One example of silicone emulsifiers which are to be used
particularly advantageously for the purposes of the present
invention are dimethicone copolyols, which are sold by the company
Th.Goldschmidt AG under the trade names ABIL.RTM. B 8842, ABIL.RTM.
B 8843, ABIL.RTM. B 8847, ABIL.RTM. B 8851, ABIL.RTM. B 8852,
ABIL.RTM. B 8863, ABIL.RTM. B 8873 and ABIL.RTM. B 88183.
Another example of interface-active substances which are to be used
particularly advantageously for the purposes of the present
invention is cetyldimethicone copolyol, which is sold by the
company Th.Goldschmidt AG under the trade name ABIL.RTM. EM 90.
A further example of interface-active substances to be used
particularly advantageously for the purposes of the present
invention is the cyclomethiconedimethicone copolyol, which is sold
by the company Th.Goldschmidt AG under the trade name ABIL.RTM. EM
97.
In addition, the emulsifier laurylmethicone copolyol has proven to
be very particularly advantageous and is available under the trade
name Dow Corning.RTM. 5200 Formulation Aid from the company Dow
Corning Ltd.
The total amount of silicone emulsifiers used according to the
invention in the cosmetic or dermatological preparations according
to the invention is advantageously chosen from the range 0.1-10.0%
by weight, preferably 0.5-5.0% by weight, based on the total weight
of the preparations.
Although it is known that W/O emulsions can be produced using
emulsifiers of the type described above, the known prior art was
nevertheless unable to indicate the route to the present
invention.
It had therefore not been foreseen by the person skilled in the art
that the preparations according to the invention would have better
effectiveness as moisture-donating preparations, would be easier to
formulate, would better promote skin smoothing, would be
characterized by better care action, would better serve as vehicles
for cosmetic and medicinal-dermatological active ingredients would
have better sensory properties, such as, for example, the ability
to be distributed on the skin or the ability to be absorbed into
the skin, would have higher stability against decomposition in oil
and water phases and would be characterized by better
biocompatibility than the preparations of the prior art.
It is possible and advantageous to choose the water content of the
W/O emulsions according to the invention to be significantly more
than 80% by weight, in particular more than 85% by weight, in each
case based on the total weight of the preparations.
Spreading is the often desired, but in other situations also often
undesired property based predominantly on capillary forces of
low-viscosity oils to be distributed in a thin layer particularly
readily on substrates or else on the skin. This may be advantageous
in skincare. This property may have an adverse effect during the
packaging of such oils or preparations containing them. One measure
of the spreadability is the spreading coefficient, which, for
example, in the case of antifoams and foam preventatives, assumes
particularly high values.
Barry and Grace developed a method to determine the spreading
behavior (J. Pharmac. Sci. 61, 335 [1972]) and Beyer developed a
model test system to test spreading behavior (Arch. Pharm. [Weinh.]
310, 729 [1977]; Chem. Abstr. 88, No. 12-79017 [1978]). The
spreading of ointments on the model is also reported by Beyer in
Arch. Pharm. 310, 473 and 858 (1977); Zbl. Pharm. 118, 51 (1979).
The spreadability of various liquid auxiliaries based on fats or
fat-like substances has been reported by Pascale et.al. (Cosmet.
Toiletries 100, No. 10, 75 [1985]).
The unit of the spreading coefficient is that of the quotient of
the spreading area over which spreading takes place, and the
spreading time in which spreading takes place. It is usually given
in [mm.sup.2 /10 minutes].
For the purposes of the present disclosure, the expression "lipids"
is sometimes used as a generic term for fats, oils, waxes and the
like, said expression being entirely familiar to the person skilled
in the art. The terms "oil phase" and "lipid phase" are also used
synonymously.
Preparations according to the invention preferably comprise up to
35% by weight of a lipid phase.
According to the teaching presented herein, W/O emulsions are
advantageously obtainable whose viscosity at 25.degree. C. is less
than 5 000 mPa.multidot.s (=millipascal seconds), in particular
less than 2 500 mPa.multidot.s, preferably less than 1 500
mPa.multidot.s (measured using Viscotester VT-02, Haake).
The oils used according to the invention are advantageously chosen
from the group of substances listed in the following table:
TABLE 1 Viscosity Spreadability mPas (20 .mu.l/red band filter)
Trade name Name analogous to INCI mPa .multidot. s mm.sup.2 /10 min
Solvent IH Isohexadecane 8 990 Isoeicosane 12 800 Cegesoft .RTM.
C24 Octyl palmitate 11 910 Isopropyl stearate 9 910 Estol .RTM.
1540 EHC Octyl cocoate 10 930 Finsolv .RTM. TN C.sub.12-15 -Alkyl
benzoate 14 730 Cetiol .RTM. OE Dicaprylyl ether 8 1020 DUB DNPG
Neopentyl glycol diheptanoate 13 830 Miglyol .RTM. 840 Propylene
glycol dicaprylate/dicaprate 12 855 DC Fluid 345 Cyclomethicone 5
770 Isopropyl palmitate 7.1 1590 Cetiol .RTM. B Dibutyl adipate 5.5
935 DUB VCI 10 Isodecyl neopentanoate 3.9 962 Cetiol .RTM. CC
Dicaprylyl carbonate 7.26 875 Cetiol .RTM. S Dioctylcyclohexane
14.41 723 Dihexyl carbonate 3.8 1056 Dihexyl ether 1.87 1174
Ecolane .RTM. 130 Cycloparaffin 5.22 908 Softcutol .RTM. O
Ethoxydiglycol oleate 13.07 804 Transcutol .RTM. CG Ethoxy diglycol
4.14 999 Dermofeel .RTM. BGC Butylene glycol caprylate/caprate 12
800 Prisorine .RTM. 2036 Octyl isostearate 15 800 Tegosoft .RTM. SH
Stearyl heptanoate 13 755 Tegosoft .RTM. DC Decyl cocoate 10.3 788
Transcutol .RTM. P Ethoxy diglycol 4.27 962 Arlasolv .RTM. DMI
Dimethyl isosorbide 10 880
Particular preference is given to dicaprylyl carbonate, dibutyl
adipate, octyl cocoate (=ethylhexyl cocoate), octyl palmitate
(=ethylhexyl palmitate), octyl isostearate (=ethylhexyl
isostearate).
Accordingly, it is preferred according to the invention to choose a
content of the lipid or of the lipids having a viscosity of less
than 15 mPa.multidot.s (at 25.degree. C.) which has a spreading
value of at least 700 mm.sup.2 /10 minutes (at 25.degree. C.) in
the lipid phase according to the invention of at least about 50% by
weight, advantageously at least about 75% by weight, particularly
advantageously at least 80% by weight, in each case based on the
total lipid phase.
The aqueous phase of the preparations according to the invention
may advantageously comprise alcohols, diols or polyols of low
carbon number, and ethers thereof, preferably ethanol, isopropanol,
propylene glycol, glycerol, ethylene glycol, ethylene glycol
monoethyl or monobutyl ether, propylene glycol monomethyl,
monoethyl or monobutyl ether, diethylene glycol monomethyl or
monoethyl ether and analogous products, and also alcohols of low
carbon number, e.g. ethanol, isopropanol, 1,2-propanediol,
glycerol.
A particular advantage of the present invention is that it permits
the use of high concentrations of polyols, in particular
glycerol.
Emulsions according to the invention preferably comprise one or
more hydrocolloids.
"Hydrocolloid" is the technical abbreviation for the more accurate
name "hydrophilic colloid". Hydrocolloids are macromolecules which
have a largely linear structure and have intermolecular forces of
interaction which permit secondary and primary valence bonds
between the individual molecules and thus the formation of a
network-like structure. Some of them are water-soluble natural or
synthetic polymers which form gels or viscous solutions in aqueous
systems. They increase the viscosity of the water by either bonding
water molecules (hydration), or else by absorbing and encapsulating
the water into their interwoven macromolecules, at the same time
restricting the mobility of the water. Such water-soluble polymers
represent a large group of chemically very different natural and
synthetic polymers whose common feature is their solubility in
water or aqueous media. A prerequisite for this is that these
polymers have a number of hydrophilic groups sufficient for the
solubility in water and are not too strongly crosslinked. The
hydrophilic groups may be nonionic, anionic or cationic in nature,
for example as follows:
--NH.sub.2 --NH--R --OH --COOH ##STR2## --COO.sup.-
--SO.sub.3.sup.- --PO.sub.3.sup.2- M.sup.+ M.sup.+ M.sup.2+
##STR3## --SH --O-- ##STR4## ##STR5## ##STR6## X.sup.- X.sup.-
##STR7## ##STR8## ##STR9## ##STR10## ##STR11## ##STR12## X.sup.-
X.sup.-
The group of cosmetically and dermatologically relevant
hydrocolloids can be divided as follows: organic, natural
compounds, such as, for example, agar agar, carrageen, tragacanth,
gum arabic, alginates, pectins, polyoses, guar flour, carob bean
flour, starch, dextrins, gelatin, casein, organic, modified natural
substances, such as, for example, carboxymethylcellulose and other
cellulose ethers, hydroxyethyl- and -propylcellulose and the like,
organic, fully synthetic compounds, such as, for example,
polyacrylic and polymethacrylic compounds, vinyl polymers,
polycarboxylic acids, polyethers, polyimines, polyamides, inorganic
compounds, such as, for example, polysilicic acids, clay minerals,
such as montmorillonite, zeolites, silicas.
Examples of hydrocolloids which are preferred according to the
invention are methylcelluloses, which is the name for the methyl
ethers of cellulose. They are characterized by the following
structural formula; ##STR13##
in which R can be a hydrogen or a methyl group.
Particularly advantageous for the purposes of the present invention
are the cellulose mixed ethers, which are generally likewise
referred to as methylcelluloses, which contain, in addition to a
dominating content of methyl groups, additionally 2-hydroxyethyl,
2-hydroxypropyl and 2-hydroxybutyl groups. Particular preference is
given to (hydroxypropyl)methylcelluloses, for example those
available under the trade name Methocel E4M from Dow Chemical
Comp.
Also advantageous according to the invention is sodium
carboxymethylcellulose, the sodium salt of the glycolic ether of
cellulose, for which R in structural formula I can be a hydrogen
and/or CH.sub.2 --COONa. Particular preference is given to the
sodium carboxymethylcellulose available under the trade name
Natrosol Plus 330 CS from Aqualon and also referred to as cellulose
gum.
For the purposes of the present invention, preference is also given
to xanthan (CAS No. 11138-66-2), also called xanthan gum, which is
an anionic heteropolysaccharide which is generally formed by
fermentation from maize sugar and is isolated as the potassium
salt. It is produced by Xanthomonas campestris and a few other
species under aerobic conditions with a molecular weight of
2.times.10.sup.6 to 24.times.10.sup.6. Xanthan is formed from a
chain having .beta.-1,4-bonded glucose (cellulose) with side
chains. The structure of the subgroups consists of glucose,
mannose, glucuronic acid, acetate and pyruvate. Xanthan is the name
for the first microbial anionic heteropolysaccharide. It is
produced by Xanthomonas campestris and a few other species under
aerobic conditions with a molecular weight of 2-15.times.10.sup.6.
Xanthan is formed from a chain having .beta.-1,4-bonded glucose
(cellulose) with side chains. The structure of the subgroups
consists of glucose, mannose, glucuronic acid, acetate and
pyruvate. The number of pyruvate units determines the viscosity of
the xanthan. Xanthan is produced in two-day batch cultures with a
yield of 70-90%, based on carbohydrate used. In this connection,
yields of 25-30 g/l are achieved. After the culture has been
killed, work-up is carried out by precipitation with e.g.
2-propanol. Xanthan is then dried and ground.
For the purposes of the present invention, another advantageous gel
former is carrageen, a gel-forming extract with a similar structure
to agar, of North Atlantic red algae which belong to the Florideae
(Chondrus crispus and Gigartina stellata).
The term carrageen is frequently used for the dried algae product
and carrageenan for the extract thereof. The carrageen precipitated
from the hot-water extract of the algae is a colorless to
sand-colored powder with a molecular weight range from 100 000-800
000 and a sulfate content of about 25%. Carrageen, which is very
readily soluble in warm water, forms a thixotropic gel on cooling,
even if the water content is 95-98%. The rigidity of the gel is
effected by the double helix structure of the carrageen. In the
case of carrageenan, three principal constituents are
differentiated: the gel-forming .kappa. fraction consists of
D-galactose 4-sulfate and 3,6-anhydro-.alpha.-D-galactose, having
alternate glycoside bonds in the 1,3 and 1,4 positions (agar, in
contrast, contains 3,6-anhydro-.alpha.-L-galactose). The
non-gelling .lambda. fraction is composed of 1,3-glycosidically
linked D-galactose 2-sulfate and 1,4-bonded D-galactose
2,6-disulfate radicals and is readily soluble in cold water.
.tau.-Carrageenan, composed of D-galactose 4-sulfate in 1,3 bond
and 3,6-anhydro-.alpha.-D-galactose 2-sulfate in 1,4 bond, is both
water-soluble and also gel-forming. Other types of carrageen are
likewise labeled with Greek letters: .alpha., .beta., .gamma.,
.mu., .nu., .xi., .pi., .omega., .chi.. The nature of cations which
are present (K.sup.+, NH.sub.4.sup.+, Na.sup.+, Mg.sup.2+,
Ca.sup.2+) also influences the solubility of the carrageens.
The use of chitosan in cosmetic preparations is known per se.
Chitosan represents a partially deacylated chitin. This biopolymer
has, inter alia, film-forming properties and is characterized by a
silky feel on the skin. A disadvantage, however, is its severe
stickiness on the skin which occurs in
particular--temporarily--during application. In individual cases
corresponding preparations may not then be marketable since they
are unacceptable to and viewed negatively by the consumer. As is
known, chitosan is used, for example, in hair care. It is suitable,
to a better degree than the chitin on which it is based, as a
thickener or stabilizer and improves the adhesion and water
resistance of polymeric films. A representative of the large number
of literature references for the prior art is: H. P. Fiedler,
"Lexikon der Hilfsstoffe fur Pharmazie, Kosmetik und angrenzende
Gebiete" [Lexikon of auxiliaries for pharmacy, cosmetics and
related fields], third edition 1989, Editio Cantor, Aulendorf, p.
293, keyword "Chitosan".
Chitosan is characterized by the following structural formula:
##STR14##
where n assumes values up to about 10 000, and X is either the
acetyl radical or hydrogen. Chitosan forms by deacetylation and
partial depolymerization (hydrolysis) of chitin, which is
characterized by the structural formula: ##STR15##
Chitin is an essential constituent of the ecto skeleton ['.omicron.
.chi..iota..tau..omega..nu.=Greek: integument] of arthropods (e.g.
insects, crabs, spiders) and is also found in supporting tissues of
other organisms (e.g. molluscs, algae, fungi).
In the region of about pH <6, chitosan is positively charged and
in that range is also soluble in aqueous systems. It is
incompatible with anionic raw materials. For this reason, to
prepare chitosan-containing oil-in-water emulsions, the use of
nonionic emulsifiers is appropriate. These are known per se, for
example from EP-A 776 657.
Preference is given according to the invention to chitosans with a
degree of deacetylation of >25%, in particular >55 to 99%
[determined by means of .sup.1 H-NMR].
It is advantageous to choose chitosans with molecular weights
between 10 000 and 1 000 000, in particular those with molecular
weights between 100 000 and 1 000 000. [determined by means of gel
permeation chromatography].
Polyacrylates are gelling agents likewise to be used advantageously
for the purposes of the present invention. Polyacrylates
advantageous according to the invention are acrylate-alkyl acrylate
copolymers, in particular those chosen from the group of so-called
carbomers or carbopols (Carbopol.RTM. is actually a registered
trademark of B. F. Goodrich Company). In particular, the
acrylate-alkyl acrylate copolymers advantageous according to the
invention are characterized by the following structure:
##STR16##
where R' is a long-chain alkyl radical, and x and y represent
numbers which symbolize the respective stoichiometric proportion of
each of the comonomers.
According to the invention, particular preference is given to
acrylate copolymers and/or acrylate-alkyl acrylate copolymers which
are available under the trade names Carbopol.RTM. 1382,
Carbopol.RTM. 981 and Carbopol.RTM. 5984 from B. F. Goodrich
Company.
Also advantageous are copolymers of C.sub.10-30 -alkyl acrylates
and one or more monomers of acrylic acid, of methacrylic acid or
esters thereof which are crosslinked with an allyl ether of sucrose
or an allyl ether of pentaerythritol.
Compounds which carry the INCI name "Acrylates/C 10-30 Alkyl
Acrylate Crosspolymer" are advantageous. Particularly advantageous
are those available under the trade names Pemulen TR1 and Pemulen
TR2 from B. F. Goodrich Company.
The total amount of one or more hydrocolloids in the finished
cosmetic or dermatological preparations is advantageously chosen to
be less than 1.5% by weight, preferably between 0.1 and 1.0% by
weight, based on the total weight of the preparations.
Hydrocolloids from the group of anionic polymers are advantageously
chosen for the purposes of the present invention from the group of
carbomers as sodium, potassium, TEA and trisamino salts, sodium,
potassium hyaluronate, microcrystalline cellulose+cellulose gum,
Veegum grades, hectorites, bentonites, laponites, alginates,
methacrylates.
Hydrocolloids from the group of nonionic polymers are
advantageously chosen for the purposes of the present invention
from the group consisting of polyvinylpyrrolidone,
hydroxypropylmethylcellulose, polyvinyl alcohol, polyether-1,
xanthan gum, hydroxyethylcellulose, cellulose derivatives, starch,
starch derivatives, guar gum, glyceryl methacrylate.
Hydrocolloids from the group of cationic polymers are
advantageously chosen for the purposes of the present invention
from the group consisting of chitosan, cationic starch derivatives,
cationic cellulose derivatives, guar hydroxypropyltrimethylammonium
chloride, sodium polystyrenesulfonate.
Particularly advantageous preparations are also obtained when
antioxidants are used as additives or active ingredients. According
to the invention, the preparations advantageously comprise one or
more antioxidants. Antioxidants which are favorable but which are
nevertheless optional may be all antioxidants which are customary
or suitable for cosmetic and/or dermatological applications.
The antioxidants are advantageously chosen from the group
consisting of amino acids (e.g. glycine, histidine, tyrosine,
tryptophan) and derivatives thereof, imidazoles, (e.g. urocanic
acid) and derivatives thereof, peptides, such as D,L-carnosine,
D-carnosine, L-carnosine and derivatives thereof (e.g. anserine),
carotenoids, carotenes (e.g. .alpha.-carotene, .beta.-carotene,
.psi.-lycopene) and derivatives thereof, lipoic acid and
derivatives thereof (e.g. dihydrolipoic acid), aurothioglucose,
propylthiouracil and other thiols (e.g. thioredoxin, glutathione,
cysteine, cystine, cystamine and the glycosyl, N-acetyl, methyl,
ethyl, propyl, amyl, butyl and lauryl, palmitoyl, oleyl,
.gamma.-linoleyl, cholesteryl and glyceryl esters thereof) and
salts thereof, dilauryl thiodipropionate, distearyl
thiodipropionate, thiodipropionic acid and derivatives thereof
(esters, ethers, peptides, lipids, nucleotides, nucleosides and
salts) and sulfoximine compounds (e.g. buthionine sulfoximines,
homocysteine sulfoximine, buthionine sulfones, penta-, hexa-,
heptathionine sulphoximine) in very low tolerated doses (e.g. pmol
to .mu.mol/kg), and also (metal) chelating agents (e.g.
.alpha.-hydroxy fatty acids, palmitic acid, phytic acid,
lactoferrin), .alpha.-hydroxy acids (e.g. citric acid, lactic acid,
malic acid), humic acid, bile acid, bile extracts, bilirubin,
biliverdin, EDTA, EGTA and derivatives thereof, unsaturated fatty
acids and derivatives thereof (e.g. .gamma.-linolenic acid,
linoleic acid, oleic acid), folic acid and derivatives thereof,
ubiquinone and ubiquinol and derivatives thereof, vitamin C and
derivatives (e.g. ascorbyl palmitate, Mg ascorbyl phosphate,
ascorbyl acetate), tocopherols and derivatives (e.g. vitamin E
acetate), vitamin A and derivatives (vitamin A palmitate) and
coniferyl benzoate of benzoin resin, rutinic acid and derivatives
thereof, ferulic acid and derivatives thereof, butylhydroxytoluene,
butylhydroxyanisole, nordihydroguaiacic acid, nordihydroguaiaretic
acid, trihydroxybutyrophenone, uric acid and derivatives thereof,
mannose and derivatives thereof, zinc and derivatives thereof (e.g.
ZnO, ZnSO.sub.4), selenium and derivatives thereof (e.g.
selenomethionine), stilbenes and derivatives thereof (e.g. stilbene
oxide, trans-stilbene oxide), and the derivatives (salts, esters,
ethers, sugars, nucleotides, nucleosides, peptides and lipids) of
said active substances which are suitable according to the
invention.
For the purposes of the present invention, oil-soluble antioxidants
can be used particularly advantageously.
A surprising property of the present invention is that preparations
according to the invention are very good vehicles for cosmetic or
dermatological active ingredients into the skin, preferred active
ingredients being antioxidants which are able to protect the skin
against oxidative stress. Preferred antioxidants are vitamin E and
derivatives thereof and vitamin A and derivatives thereof.
The amount of antioxidants (one or more compounds) in the
preparations is preferably from 0.001 to 30% by weight,
particularly preferably 0.05-20% by weight, in particular 1-10% by
weight, based on the total weight of the preparation.
If vitamin E and/or derivatives thereof are used as the antioxidant
or antioxidants, the respective concentrations thereof are
advantageously chosen from the range 0.001-10% by weight, based on
the total weight of the formulation.
If vitamin A or vitamin A derivatives or carotenes or derivatives
thereof are used as the antioxidant or antioxidants, the respective
concentrations thereof are advantageously chosen from the range
0.001-10% by weight, based on the total weight of the
formulation.
The person skilled in the art is of course aware that cosmetic
preparations are in most cases inconceivable without the customary
auxiliaries and additives. The cosmetic and dermatological
preparations according to the invention can, accordingly, also
comprise cosmetic auxiliaries, as are customarily used in such
preparations, for example bodying agents, stabilizers, fillers,
preservatives, perfumes, antifoams, dyes, pigments which have a
coloring action, thickeners, surface-active substances,
emulsifiers, emollients, moisturizers and/or humectants,
anti-inflammatory substances, additional active ingredients such as
vitamins or proteins, sunscreens, insect repellants, bactericides,
virucides, water, salts, antimicrobial, proteolytic or keratolytic
substances, medicaments or other customary constituents of a
cosmetic or dermatological formulation such as alcohols, polyols,
polymers, foam stabilizers, organic solvents or also
electrolytes.
The latter can be chosen, for example, from the group of salts
containing the following anions: chlorides, also inorganic oxo
element anions, of these, in particular sulfates, carbonates,
phosphates, borates and aluminates. Electrolytes based on organic
anions are also advantageous, e.g. lactates, acetates, benzoates,
propionates, tartrates, citrates, amino acids,
ethylenediaminetetraacetic acid and salts thereof and others.
Preferred cations of the salts are ammonium, alkylammonium, alkali
metal, alkaline earth metal, magnesium, iron or zinc ions. It does
not need to be mentioned that only physiologically acceptable
electrolytes should be used in cosmetics. Particular preference is
given to potassium chloride, sodium chloride, magnesium sulfate,
zinc sulfate and mixtures thereof.
Corresponding requirements apply mutatis mutandis to the
formulation of medicinal preparations.
The W/O emulsions according to the invention can be used as a base
for cosmetic or dermatological formulations. The latter can have
the customary composition and be used, for example, for the
treatment and care of the skin and/or the hair, as lip care
product, as deodorant product and as make-up or make-up remover
product in decorative cosmetics or as a sunscreen preparation. For
use, the cosmetic and dermatological preparations according to the
invention are applied to the skin and/or the hair in a sufficient
amount in a manner customary for cosmetics or dermatological
compositions.
For the purposes of the present invention, cosmetic or topical
dermatological compositions can accordingly, depending on their
composition, be used, for example, as a skin protection cream,
cleansing milk, sunscreen lotion, nourishing cream, day or night
cream, etc. In some circumstances it is possible and advantageous
to use the compositions according to the invention as a base for
pharmaceutical formulations.
The low-viscosity cosmetic or dermatological compositions according
to the invention can, for example, be in the form of preparations
which can be sprayed from aerosol containers, squeezable bottles or
by means of a pump device, or in the form of a liquid composition
which can be applied by means of roll-on devices, but also in the
form of an emulsion which can be applied from normal bottles and
containers.
Suitable propellants for cosmetic or dermatological preparations
which can be sprayed from aerosol containers for the purposes of
the present invention are the customary known readily volatile,
liquefied propellants, for example hydrocarbons (propane, butane,
isobutane), which can be used alone or in a mixture with one
another. Compressed air is also used advantageously.
The person skilled in the art is of course aware that there are
propellants which are non-toxic per se which would be suitable in
principle for realizing the present invention in the form of
aerosol preparations, but which must nevertheless be avoided
because of their unacceptable impact on the environment or other
accompanying circumstances, in particular fluorocarbons and
chlorofluorocarbons (CFCs).
Those cosmetic and dermatological preparations which are in the
form of a sunscreen are also favorable. As well as the active
ingredient combinations according to the invention, these
preferably additionally comprise at least one UV-A filter substance
and/or at least one UV-B filter substance and/or at least one
inorganic pigment.
For the purposes of the present invention, however, it is also
advantageous to provide cosmetic and dermatological preparations
whose main purpose is not protection against sunlight, but which
nevertheless have a content of UV protectants. Thus, for example,
UV-A or UV-B filter substances are usually incorporated into day
creams.
UV protectants, like antioxidants and, if desired, preservatives,
also effectively protect the preparations themselves against
decay.
Preparations according to the invention can advantageously comprise
further substances which absorb UV radiation in the UV-B range, the
total amount of filter substances being, for example, from 0.1% by
weight to 30% by weight, preferably from 0.5 to 10% by weight, in
particular from 1.0 to 6.0% by weight, based on the total weight of
the preparations, in order to provide cosmetic preparations which
protect the hair and/or the skin from the whole region of
ultraviolet radiation. They can also be used as sunscreens for the
hair or the skin.
If the emulsions according to the invention comprise UV-B filter
substances, the latter may be oil-soluble or water-soluble.
Examples of oil-soluble UV-B filters which are advantageous
according to the invention are: 3-benzylidenecamphor derivatives,
preferably 3-(4-methylbenzylidene)camphor, 3-benzylidenecamphor;
4-aminobenzoic acid derivatives, preferably 2-ethylhexyl
4-(dimethylamino)benzoate, amyl 4-(dimethylamino)benzoate; esters
of cinnamic acid, preferably 2-ethylhexyl 4-methoxycinnamate,
isopentyl 4-methoxycinnamate; esters of salicylic acid, preferably
2-ethylhexyl salicylate, 4isopropylbenzyl salicylate, homomenthyl
salicylate; derivatives of benzophenone, preferably
2-hydroxy-4methoxybenzophenone,
2-hydroxy-4-methoxy-4'-methylbenzophenone,
2,2'-dihydroxy-4-methoxybenzophenone; esters of benzalmalonic acid,
preferably di(2-ethylhexyl) 4-methoxybenzalmalonate; derivatives of
1,3,5-triazine, preferably
2,4,6-trianilino(p-carbo-2'-ethyl-1'-hexyloxy)-1,3,5-triazine.
The list of said UV-B filters, which may be used in combination
with the active ingredient combinations according to the invention
is of course not intended to be limiting.
It can also be advantageous to formulate lipodispersions according
to the invention with UV-A filters which have hitherto been
customarily present in cosmetic preparations. These substances are
preferably derivatives of dibenzoylmethane, in particular
1-(4'-tert-butylphenyl)-3-(4'-methoxyphenyl)propane-1,3-dione and
1-phenyl-3-(4'-isopropylphenyl)propane-1,3-dione.
Cosmetic and dermatological preparations according to the invention
can also comprise inorganic pigments which are customarily used in
cosmetics for protecting the skin against UV rays. These are oxides
of titanium, zinc, iron, zirconium, silicon, manganese, aluminum,
cerium and mixtures thereof, and modifications in which the oxides
are the active agents. Particular preference is given to pigments
based on titanium dioxide.
Further constituents which can be used are: fats, waxes and other
natural and synthetic fatty substances, preferably esters of fatty
acids with alcohols of low carbon number, e.g. with isopropanol,
propylene glycol or glycerol, or esters of fatty alcohols with
alkanoic acids of low carbon number or with fatty acids; alcohols,
diols or polyols of low carbon number, and ethers thereof,
preferably ethanol, isopropanol, propylene glycol, glycerol,
ethylene glycol, ethylene glycol monoethyl or monobutyl ethers,
propylene glycol monomethyl, monoethyl or monobutyl ethers,
diethylene glycol monomethyl or monoethyl ethers and analogous
products.
Preparations according to the invention can also comprise active
ingredients (one or more compounds) which are chosen from the
group: acetylsalicylic acid, atropine, azulene, hydrocortisone and
derivatives thereof, e.g. hydrocortisone-17 valerate, vitamins,
e.g. ascorbic acid and derivatives thereof, vitamins of the B and D
series, very favorably vitamin B.sub.1, vitamin B.sub.12 and
vitamin D.sub.1, but also bisabolol, unsaturated fatty acids,
namely the essential fatty acids (often also called vitamin F), in
particular .gamma.-linolenic acid, oleic acid, eicosapentanoic
acid, docosahexanoic acid and derivatives thereof, chloramphenicol,
caffeine, prostaglandins, thymol, camphor, extracts or other
products of a vegetable and animal origin, e.g. evening primrose
oil, borage oil or currant seed oil, fish oils, cod-liver oil or
also ceramides or ceramide-like compounds etc. It is also
advantageous to choose the active ingredients from the group of
refatting substances, for example purcellin oil, Eucerit.RTM. and
Neocerit.RTM..
The amount of such active ingredients (one or more compounds) in
the preparations according to the invention is preferably from
0.001 to 30% by weight, particularly preferably 0.05-20% by weight,
in particular 1-10% by weight, based on the total weight of the
preparation.
The examples below serve to illustrate the present invention
without limiting it. The numerical values in the examples refer to
percentages by weight, based on the total weight of the respective
preparations.
EXAMPLE 1
% by wt. Cetyldimethicone copolymer 1.0 Isopropyl palmitate 3.0
Cetiol CC 4.5 Cyclomethicone 5.0 Glycerol 3.0 Chitosan 0.25 Lactic
acid 0.15 NaCl 1.0 Perfume, preservative, dyes, antioxidants q.s.
Water ad 100.0
EXAMPLE 2
% by wt. Cetyldimethicone copolymer 1.5 C.sub.12-15 -Alkyl
benzoates 10.0 Glycerol 3.0 Sodium polystyrenesulfonate 1.0
MgSO.sub.4 0.7 Perfume, preservative, dyes, antioxidants q.s. Water
ad 100.0
EXAMPLE 3
% by wt. Cetyldimethicone copolymer 1.5 Octyl cocoate 10.0 Glycerol
3.0 Guar hydroxypropyltrimethylammonium chloride 1.0 MgSO.sub.4 0.7
Perfume, preservative, dyes, antioxidants q.s. Water ad 100.0
EXAMPLE 4
% by wt. Cetyldimethicone copolymer 1.5 Isopropyl stearate 10.0
Glycerol 3.0 Sodium polystyrenesulfonate 0.5 MgSO.sub.4 0.7
Perfume, preservative, dyes, antioxidants q.s. Water ad 100.0
EXAMPLE 5
% by wt. Cetyldimethicone copolymer 2.0 Dicaprylyl carbonate 10.0
Glycerol 3.0 Sodium chloride 1.0 Guar
hydroxypropyltrimethylammonium chloride 1.0 Perfume, preservative,
dyes, antioxidants q.s. Water ad 100.0
EXAMPLE 6
% by wt. Cetyldimethicone copolymer 1.5 Dicaprylyl ether 10.0
Chitosan 0.25 Salicylic acid 0.15 Glycerol 3.0 MgSO.sub.4 0.7
Perfume, preservative, dyes, antioxidants q.s. Water ad 100.0
EXAMPLE 7
% by wt. Cetyldimethicone copolymer 1.5 Butylene glycol
dicaprylate/dicaprate 10.0 Glycerol 3.0 MgSO.sub.4 0.7 Chitosan 2.5
Acetic acid 1.5 Perfume, preservative, dyes, antioxidants q.s.
Water ad 100.0
EXAMPLE 8
% by wt. Cetyldimethicone copolymer 1.5 Dioctylcyclohexane 10.0
Glycerol 3.0 MgSO.sub.4 0.7 Chitosan 0.25 Citric acid 0.15 Perfume,
preservative, dyes, antioxidants q.s. Water ad 100.0
* * * * *